Index: Lib/email/test/test_email.py
===================================================================
--- Lib/email/test/test_email.py	(revision 63020)
+++ Lib/email/test/test_email.py	(working copy)
@@ -2550,7 +2550,11 @@
         eq(headers, ['A', 'B', 'CC'])
         eq(msg.get_payload(), 'body')
 
+    def test_multipart_with_invalid_cte(self):
+        msg = self._msgobj("msg_45.txt")
+        self.assertNotEqual(0, len(msg.defects))
 
+
 
 class TestBase64(unittest.TestCase):
     def test_len(self):
Index: Lib/email/errors.py
===================================================================
--- Lib/email/errors.py	(revision 63020)
+++ Lib/email/errors.py	(working copy)
@@ -55,3 +55,6 @@
 
 class MultipartInvariantViolationDefect(MessageDefect):
     """A message claimed to be a multipart but no subparts were found."""
+
+class InvalidContentTransferEncoding(MessageDefect):
+    """A Content-Transfer-Encoding for multpart is invalid."""
Index: Lib/email/feedparser.py
===================================================================
--- Lib/email/feedparser.py	(revision 63020)
+++ Lib/email/feedparser.py	(working copy)
@@ -209,6 +209,20 @@
         # Done with the headers, so parse them and figure out what we're
         # supposed to see in the body of the message.
         self._parse_headers(headers)
+
+
+        # If an email has an entity of multipart kind, its encoding must be
+        # either 7bit, 8bit, or binary, says [1].
+        #
+        # [1]: http://tools.ietf.org/html/rfc2045#section-6.4
+        #
+        cte = self._cur.get('Content-Transfer-Encoding')
+        ct = self._cur.get('Content-Type')
+        if ct and cte:
+            if ct.startswith('multipart') and cte not in ['7bit', '8bit', 'binary']:
+                defect = errors.InvalidContentTransferEncoding()
+                self._cur.defects.append(defect)
+
         # Headers-only parsing is a backwards compatibility hack, which was
         # necessary in the older parser, which could throw errors.  All
         # remaining lines in the input are thrown into the message body.